Parallel structure- is using the same grammatical form to express two or more equal, or parallel, ideas. This is where you would Pairing adjectives with adjectives, prepositional phrases with prepositional, noun clauses with noun clauses this emphasizes the relationship between the ideas.
Example–(correct) My brother likes to jog, to read, to eat everyday.
Example-(correct) I run, eat, and shower in the morning before school.
Example-(correct) The students have been studying, preparing, and reviewing for their upcoming test. Example-(incorrect) My brother likes jogging, to eat and reading everyday.
Example-(incorrect) Jimmy likes writing, reading and to sleep.
Parallel structure- is using the same grammatical form to express two or more equal, or parallel, ideas. This is where you would Pairing adjectives with adjectives, prepositional phrases with prepositional, noun clauses with noun clauses this emphasizes the relationship between the ideas.
Example–(correct) My brother likes to jog, to read, to eat everyday.
Example-(correct) I run, eat, and shower in the morning before school.
Example-(correct) The students have been studying, preparing, and reviewing for their upcoming test.
Example-(incorrect) My brother likes jogging, to eat and reading everyday.
Example-(incorrect) Jimmy likes writing, reading and to sleep.
Parallel Structure is the same as Parallelism.
Here are some links to help you furthermore understand Parallel Structure!
http://owl.english.purdue.edu/owl/resource/623/01/
http://grammar.ccc.commnet.edu/grammar/parallelism.htm
http://www.evergreen.edu/writingcenter/handouts/grammar/parallel.pdf
http://www.d.umn.edu/~dmorriso/readablewriting/Parallelstructure/Index.html
http://eslbee.com/parallel_structure.htm
http://homepages.cambrianc.on.ca/tutorial/thetutorialcentre/writing/parallel_structure.htm
http://grammar.about.com/od/pq/g/parallelstructureterm.htm